Skylark Bio doses first patient in gene therapy trial for GJB2-related deafness

Aug 11, 2026

Skylark Bio has dosed the first pediatric patient in its SONIX Phase 1/2 clinical trial, evaluating the investigational gene therapy SKY-GJB2. The trial targets GJB2-related hearing loss, the most common genetic cause of congenital deafness, which currently has no approved disease-modifying treatments. SKY-GJB2 delivers a functional gene copy to restore essential inner-ear proteins. Supported by the FDA's April 2026 approval of Regeneron's Otarmeni, Skylark Bio expects preliminary data by the end of 2026.

SONIX trial first patient dosing

▪The SONIX trial is a multicenter, open-label Phase 1/2 study evaluating a single unilateral intracochlear injection of SKY-GJB2 in children aged 9 months to 7 years.
▪Skylark Bio announced on August 11, 2026, that the first pediatric patient has been dosed in its SONIX Phase 1/2 clinical trial evaluating the investigational gene therapy SKY-GJB2.
▪The SONIX clinical trial is designed to generate preliminary data by the end of 2026, with additional readouts anticipated in 2027.

SKY-GJB2 gene therapy mechanism

▪SKY-GJB2 is designed to deliver a functional copy of the GJB2 gene to supporting cells in the cochlea to restore the gap-junction network essential for hearing.
▪Skylark Bio is developing a pipeline of genetic therapies, including SKY-GJB2, SKY-PEN for SLC26A4-related hearing loss, and an undisclosed program in the central nervous system.

GJB2-related hearing loss prevalence

▪GJB2-related hearing loss is the most common genetic cause of nonsyndromic deafness and the leading cause of inherited hearing loss worldwide.
▪Genetic changes in the GJB2 gene disrupt the function of connexin 26, a protein essential to the gap-junction network of the inner ear.

Current treatment limitations

▪Current interventions for GJB2-related hearing loss, such as hearing aids and cochlear implants, provide access to sound but do not address the underlying genetic cause.
▪There are currently no approved disease-modifying treatments available for GJB2-related hearing loss.

Gene therapy field validation

▪The Food and Drug Administration approved Regeneron's Otarmeni therapy in April 2026 for genetic hearing loss caused by otoferlin-related mutations.
▪Skylark Bio CEO Jodi Cook stated that the recent approval of a targeted inner-ear adeno-associated virus-delivered therapy provides validation and reinforces confidence in Skylark Bio's approach.